package utils;


import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.Arrays;
import java.util.Random;

public class VerifyCodeUtil {
    public static final String VERIFY_CODES = "123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    //不要0，避免与O混淆
    private static Random random = new Random();
    /***
     *  输出随机验证码图片流,并返回验证码值（一般传入输出流，响应response页面端，Web项目用的 较多）
     ** @param w
     * @param h
     * @param os
     * @param verifySize 验证码长度
     * @return
     * @throws IOException
     */ public static String outputVerifyImage(int w, int h, OutputStream os, int verifySize) throws IOException {
         String verifyCode = generateVerifyCode(verifySize);
         outputImage(w, h, os, verifyCode);
         return verifyCode;
     }/**
     * 使用系统默认字符源生成验证码
     *
     * @param verifySize 验证码长度
     * @return
     * */
     public static String generateVerifyCode(int verifySize) {
         return generateVerifyCode(verifySize, VERIFY_CODES);
     }
     /**
      * 使用指定源生成验证码
      *
      * @param verifySize 验证码长度
      * @param sources 验证码字符源
      * @return
      */
     public static String generateVerifyCode(int verifySize, String sources) {
         // 未设定展示源的字码，赋默认值大写字母+数字
         if (sources == null || sources.length() == 0) {
             sources = VERIFY_CODES;
         }
         int codesLen = sources.length();
         Random rand = new Random(System.currentTimeMillis());
         StringBuilder verifyCode = new StringBuilder(verifySize);

    for (   int i = 0; i < verifySize; i++) {
        verifyCode.append(sources.charAt(rand.nextInt(codesLen - 1)));
    }
    return verifyCode.toString();
     }
     /**
      * 生成随机验证码文件,并返回验证码值 (生成本地图片文件形式，用的较少)
      * @param w
      * @param h
      * @param outputFile
      * @param verifySize
      * @return
      * @throws IOException
      */
     public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException {
         String verifyCode = generateVerifyCode(verifySize);
         outputImage(w, h, outputFile, verifyCode);
         return verifyCode;
     }

    public static void main(String[] args)throws IOException {
        File file = new File("D:/aaa.jpg");
        String s = VerifyCodeUtil.outputVerifyImage(100, 40, file, 4);
        System.out.println(s);
    }

     /**
      * 生成指定验证码图像文件
      *
      * @param w
      * @param h
      * @param outputFile
      * @param code
      * @throws IOException
      */
     public static void outputImage(int w, int h, File outputFile, String code) throws IOException {
         if (outputFile == null) {
             return;
         }
     }


//    File dir = outputFile.getParentFile();
//     //文件不存在
//    if (!dir.exists()){
//        //创建
//        dir.mkdirs();
//    }
//    try {
//        outputFile.createNewFile();
//        FileOutputStream fos = new FileOutputStream(outputFile);
//        outputImage(w, h, fos, code);
//        fos.close();
//    }
//    catch (IOException e) {
//        throw e;
//    }
//}
/**
 * 输出指定验证码图片流
 * @param w
 * @param h
 * @param os
 * @param code
 * @throws IOException
 */
public static void outputImage(int w, int h, OutputStream os, String code) throws IOException {
    int verifySize = code.length();
    BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
    Random rand = new Random();
    Graphics2D g2 = image.createGraphics();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    // 创建颜色集合，使用java.awt包下的类
    Color[] colors = new Color[5];
    Color[] colorSpaces = new Color[]{Color.WHITE, Color.CYAN, Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE, Color.PINK, Color.YELLOW};
    float[] fractions = new float[colors.length];
    for (int i = 0; i < colors.length; i++) {
        colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
        fractions[i] = rand.nextFloat();
    }
    Arrays.sort(fractions);
    // 设置边框色
    g2.setColor(Color.GRAY);
    g2.fillRect(0, 0, w, h);
    Color c = getRandColor(200, 250);
    // 设置背景色
    g2.setColor(c);
    g2.fillRect(0, 2, w, h - 4);
    // 绘制干扰线
    Random random = new Random();
    // 设置线条的颜色
    g2.setColor(getRandColor(160, 200));
    for (int i = 0; i < 20; i++) {
        int x = random.nextInt(w - 1);
        int y = random.nextInt(h - 1);
        int xl = random.nextInt(6) + 1;
        int yl = random.nextInt(12) + 1;
        g2.drawLine(x, y, x + xl + 40, y + yl + 20);
    }
    // 添加噪点
    // 噪声率
    float yawpRate = 0.05f; int area = (int) (yawpRate * w * h);
    for (int i = 0; i < area; i++) {
        int x = random.nextInt(w);
        int y = random.nextInt(h);
        // 获取随机颜色
        int rgb = getRandomIntColor();
        image.setRGB(x, y, rgb);
    }
    // 添加图片扭曲
    shear(g2, w, h, c);
    // 文字颜色
    g2.setColor(getRandColor(120, 160));
    int fontSize = h - 4;
    Font font = new Font("Algerian", Font.ITALIC, fontSize);
    g2.setFont(font);
    char[] chars = code.toCharArray();
    for (int i = 0; i < verifySize; i++) {
        AffineTransform affine = new AffineTransform();
        affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1)
                , (w / verifySize) * i + fontSize / 2, h / 2);
        g2.setTransform(affine);
        g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);
    }
    g2.dispose();
    ImageIO.write(image, "png", os);
}
/**
 * 随机颜色
 * @param fc
 * @param bc
 * @return
 */
private static Color getRandColor(int fc, int bc) {
    if (fc > 255) {
        fc = 255;
    }
    if (bc > 255) {
        bc = 255;
    }
    int r = fc + random.nextInt(bc - fc);
    int g = fc + random.nextInt(bc - fc);
    int b = fc + random.nextInt(bc - fc);
    return new Color(r, g, b);
}
private static int getRandomIntColor() {
    int[] rgb = getRandomRgb();
    int color = 0;
    for (int c : rgb) {
        color = color << 8;
        color = color | c;
    }
    return color;
}
private static int[] getRandomRgb() {
    int[] rgb = new int[3];
    for (int i = 0; i < 3; i++) {
        rgb[i] = random.nextInt(255);
    }
    return rgb;
}
private static void shear(Graphics g, int w1, int h1, Color color) {
    shearX(g, w1, h1, color);
    shearY(g, w1, h1, color);
}
private static void shearX(Graphics g, int w1, int h1, Color color) {
    int period = random.nextInt(2);
    boolean borderGap = true;
    int frames = 1;
    int phase = random.nextInt(2);
    for (int i = 0; i < h1; i++) {
        double d = (double) (period >> 1) * Math.sin((double) i / (double) period + (6.2831853071795862D * (double) phase) / (double) frames);
        g.copyArea(0, i, w1, 1, (int) d, 0); if (borderGap) {
            g.setColor(color);
            g.drawLine((int) d, i, 0, i);
            g.drawLine((int) d + w1, i, w1, i);
        }
    }
}
private static void shearY(Graphics g, int w1, int h1, Color color) {
    int period = random.nextInt(40) + 10;
    // 50;
    boolean borderGap = true;
    int frames = 20;
    int phase = 7;
    for (int i = 0; i < w1; i++) {
        double d = (double) (period >> 1) * Math.sin((double) i / (double) period + (6.2831853071795862D * (double) phase) / (double) frames);
        g.copyArea(i, 0, 1, h1, 0, (int) d);
        if (borderGap) {
            g.setColor(color);
            g.drawLine(i, (int) d, i, 0);
            g.drawLine(i, (int) d + h1, i, h1);
        }
    }
}
}